Cathode ray tube and process



May 18, 1943 s. J. KOCH ETAL CATHODE RAY TUBE AND PROCESS Filed May 29,1942 3? 6 44/ INVENTORS HTTO/PNEV support 2 is inserted in the neck I.

"Patented May 18, 1943' cs'rnonn an runs is rnocsss Stanley J. Koch,Clifton, and Robert E. Rutherford, Rutherford, N. L, aasignors to AllenB. Du Mont Laboratories, 1110., Passaic, N. 1., a

corporation of Delaware Application May 29, 1942, Serial No. 444,961

14 Claims.

This invention relates to a cathode ray tube and the process oiproducing the same. The tube is of the sort in which the electrical gunassembly is attached to and supported by the conductors that passthrough the glass press of the tube.

By this invention the conductors are sealed in place in such a way thatthey are spaced as far apart as is feasible since they are located onthe circumference of a circle that is almost as large as the inside ofthe neck of the tube. In this way the wires are placed so far apart thatthere is maximum insulation between them. Also a. very large exhausttubulation can be used, thus facilitating rapid pumping of the tubealter the tubulation has been sealed in place.

The invention will be understood irom the description in connection withthe accompanying drawing, in which:

Fig. 1 is a longitudinal section through the neck 01' a tube along theline l-l of Fig. 2;

Fig. 2 is a section along the line 2-2 of Fig. 1:

Figs. 3 and 4 are longitudinal sections on an enlarged scale partlybroken away showing steps in the process of manufacturing the tube; and

Fig. 5 is a section along the line 5-5 of Fig. 4.

In the drawing, reference character I indicates the neck of a cathoderay tube. A mandrel or This mandrel is provided with a circular seriesoi. longitudinally extending holes 3 near its outer edge and a largercentral longitudinally extending hole 4 at its center. An integralextension I in the form of a truncated cone is provided at the upper endof the mandrel 2. I 4

The exhaust tabulation comprises a central tube 8 having a flange 9 withrecesses or scallops along its outer edge. These recesses may be made byheating the edge of the flange and pressing inwardly and downwardly witha rod of suitable diameter at spaced intervals, thus producing therecesses I. and leaving an inwardly curved integral depending flange orlip I I at each recess III.

The tubulation 8 is placed upon the mandrel 2 with the flange 9 restingupon the extension 5. Wires I2 having glass beads I3 fused thereon passthrough the holes 3 of the mandrel 2 with the beads I! in the recessesll, with these beads fitting in these recesses and in the curved lipsII.

The disc I4 is of mica and is provided with holes I5 therethrough witheyelets I. in these holes. The conductors or wires [2 pass through theeyelets l6, thus supporting this disc and the un structure of the tube,not shown.

- After the parts are assembled as indicated in place.

After the sealing is finished the exhaust tubu- Fig. 1 they are insertedinto the neck I of the tube with the edge of the flange I fitting theneck I. Heat is then applied at the level of the torch it around thewhole circumference to fuse a circular area of the glass of the neck I,the beads It; the lips II and edge of flange 9 together so that theybecome integrated as indicated in Figs. 4 and 5 with the wires I! closeto the inside surface of the wall of the neck I. One or more blowtorches may be used to apply the heat to the outside of the neck I on alevel with the beads I and the tube or'the torches may be rotated whilethe heating takes place. Any excess portion of the neck I-below theheating zone may be permitted to drop off or the beads I3 and heatingzone may be located so near the end of the neck I that no excess glassneeds to be removed. By proportioning and locating the glass elementswith respect to each other the tubulation with the neck I can be made insuch a manner that no excess glass needs to be removed and a smoothhermetically sealed joint without excessive thickness results.

With this invention it is not necessary to make a glass press throughwhich the conductors or wires are hermetically sealed and subsequentlyheat this press to seal it to the tube because the same' heating thatseals the disc I to the tube neck I also hermetically seals the wires I2in lation 8 is attached to a vacuum system and the tube is pumped out toexhaust the air in the known way and sealed oil.

The entire gun structure of a cathode ray tube can be mounted upon thewires I2 and disc I4 and adjusted and inserted into the neck I of theglass tube preparatory to the heat sealing and evacuating steps. Thisinvention is applicable to vacuum tubes in general as well as cathoderay tubes. v

What is claimed is:

1. In the process of producing a cathode ray tube, the steps whichcomprise introducing into the neck of a glass tube an exhausttubulatio'n having a flange with a serrated edge and having electricconductors in the serrations and applying suilicient heat to said neckand flange to fuse them together.

2. In the process of producing a cathode ray tube, the steps whichcomprise introducing into the neck of a glass tube an exhaust tubulationhaving a glass beaded flange with a serrated edge and having electricconductors in the serjunction of the rations and applying sumcient heatto said neck and flange to fuse them together.

3. In the process of producing a cathode ray tube, the steps whichcomprise introducing into the neck of a glass tube an exhaust tubulationhaving a glass beaded flange with a serrated edge and having electricconductors in the serrations, said serrations being substantially thesize of said. beads and applying suiflclent heat to said neck and flangeto fuse them together.

4. In the process of producing a cathode ray tube, the steps whichcomprise introducing into the neck of a glass tube an exhaust tubulationhaving a flange with a serrated edge and depending portions and havingelectric conductors in the serrations and applying suflicient heat tosaid neck and flange to fuse them together.

5. In the process of producing a cathode ray tube, the steps whichcomprise introducing into the neck of a glass tube an exhaust tubulationhaving a glass beaded flange with a serrated edge and depending portionscurved to accommodate the beads and having electric conductors in theserrations and applying sumcient heat to said neck and flange to fusethem together.

6. In the process of producing a cathode ray tube, the steps whichcomprise introducing into the neck of a glass tube an exhaust tubulationhaving a flange with a serrated edge and having electric conductors inthe serrations, and applying heat to the outside of said neck inproximity to said flange.

7. In the process of producing a,cathode ray tube, the steps whichcomprise introducing into the neck of a glass tube an exhaust tubulationhaving a flange with a serrated edge and havin electric conductors inthe serrations, and applying heat to the outside of said neck inproximity to said flange until said neck, beads and flange are fusedtogether.

8. A vacuum tube element comprising an exhaust tubulation having aserrated flange.

9. A vacuum tube element comprising an exhaust tubulation having aserrated flange and depending lips at the serrations.

10. A vacuum tube element comprising an exhaust tubulation having aserrated flange and depending inwardly curved lips at the serra--,tions.

11. A vacuum tube assembly comprising an exhaust tubulation having aserrated flange and beaded wires in said serrations.

12. A vacuum tube assembly comprising an exhaust tubulation having aserrated flange with depending portions at the ends of the serrations.

13. A vacuum tube assembly comprising an ex haust tubulation having aserrated flange with depending curved portions at the ends of theserrations.

14. A vacuum tube assembly comprising an exhaust tubulation having aserrated flange and headed wires in said serrations. the diameter of therespective beads on the wires being substantially the same as thetransverse dimension of the corresponding serration.

STANLEY J. KOCH. ROBERT E. RUTHERFORD.

